Process of making acetyl isoborneol



are

ROLAND L. ANDREAU, F VTILMING'ION, DELAWARE, ASSIGNOR TO ELI. DUPOINT-DE NEIMOURS AND COMYANY, OE VTILMINGTON, DELAWARE, A CORPORATIONOF DELAWARE.

at sse.

Ne Drawing.

To all whom it may concern Be it known that I, ROLAND L. ANDREAU,

' full, clear, and exact description thereof.

My invention relates particularly to the process for producing acetyliso-borneol,

Specification of Letters Patent.

Application filed July 7,

ljtOQESS OF MAKING: ACETYL ISOIBORNEOL.

Patented June 20,1922. 1917. Serial Nd. 179,128.

For example I may proceed as follows:

I introduce 100 kilograms of glacial acetic acid, of 9799 strength intoa still and. then add slowly thereto 1,5()0 grams'ot concentratedsulphuric acid, 95% H SO so that it becomes thoroughly dissolved bystirring.

I then add 40 kilograms of camphene and the entire mass is stirred andheated from about to 66 C. for three hours, thus completing thereaction. 2.5 kilograms of anhy- 'especiall,y for use in the commercial'prodrous sodium acetate arethen added at once,

ductiron of synthetic camphor, but has 2110 and the mass stirred verythoroughly. The

plication to other uses including the production of other acetyloxy-dihydro-terpenes. The object of my invention is to provide a processof making acetyl iso-borneol and other acetyl oxy-dihydro-terpenes in anadvantageousmanner and inwhich, when glacial acetic acid is used, themost of the said acetic acid is recovered in a suitable strength, sothat it maybe used overcontinuously without any great loss thereof.

A further object is to maintain the excess acetic acid is distilledover, under reduc'ed. pressure, thus recovering the greater portionthereof at a strength suitable for further use in the process, untilonly acetyl iso-borneol and neutral sodium sulphate remain in the still,When the acetic acid used at the start has a strength of 97% the re--covered acetic acid which is suitable for use in the next operation hasa strength of 96% The sodium sulphate is either filtered off or washedout with water and the acetyl isostrength of the glacial acetic acidsothat it borneol remains. I Instead-of using acetic of effectiveness.Hitherto acetyl iso-borneol may be used repeatedly with the samedegreeacid, I may, if desired, use formic acid, prohas been prepared bytreating eamphene centrated sulphuric acid it is also possible withglacial acetic acid and 50 strength sulphuric acid, after which themixture was drowned in water. When the process 15 carried out in thatmanner, the acetic acid becomes diluted to a point where it cannot beused again without regeneration. Even distillation in vacuo to recoverthe acetic acid, would not result in the recovery of any large part ofthe acid in concentrated form.

Furthermore, when it was desired to recover the acetic acid bydistillation, the sulphuric.

then before-distilling under reduced pres sure the excess acetic acid,adding a.neutralizing agent, for crample, a neutral an hydrous acetatewhich is acted upon by the li plouric acid to produce free glacialacetic acid. and a neutral sulphate which latter d es not aii'ect theother substances ntescnt. In this way the greater portion of the aceticacid may he obtained. at a stre'z'igth suitable .ior further use in theprocess.

to use some -othe r mineral acid such as phosphoric acid,

While I have described my invention above in detail I wish it to. beunderstood .pionic acid, etc. -.Instead of using the con sulfuric acidat a temperature of from about 55F to 66 (7. until the reaction issubstantially completed, neutralizing the sulfuric ,aeidwithsubstantially anhydrous sodium acetate, distilling off the resultingacetic acid under reduced pressure, and then removing ,fi'oniitlieresidue the sodium sulphate formed by the neutralization,

In testimony that I claim the foregoing I have hereunto set my hand.

ROLAND L. ANDREAU.

'Witnesscs CI-ZAS.. nwm, Jxz,

, Fraser G. CARPENTER.

